i was curious and looked into it a bit. first footnote is pointing out that she was a professor*, which feels like the editor throwing shade. he does seem to drop titles with people he is closer with, but i think it is pretty sus here.
*he seems to favor professor over doctor as a title
An interesting point. If they wrote often and had some friendly intimacy, it would be more likely that he would drop the "Frau Doktor" formalities. One would have to see how he wrote his letters to his male colleagues with which he was similarly friendly.
in fairness, this is probably a stylistic difference from another academic culture/era (i don’t know enough to say either way but these conventions have changed a fair bit over time)
This is a personal letter, not a professional one, would be very weird to address someone you know personally to ask them if they are OK as Dr… (at least I have never done that to my colleagues known personally).
I believe this is normal in german, his native language, not every language has a separate special title for people who earn an advanced degree. He probably just never adjusted his english speech patterns to the normal english usage.
